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- The effect of panel height on performance of ceiling radiant cooling system has been studied. Investigation has been done by employing solution of conservative equations, together with the radiant and thermal comfort equations. Calculation is performed for the typical hottest day of Tehran. Vapour condensation is one of the most important problems whit these systems. Therefore effect of panel height on condensation has been also studied, in a residential place with several different ranges of ventilation rate. The results show that appropriate design of the panel height can significantly reduce the rate of condensation.

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In this paper the problem of coupled radiation and natural convection is investigated in a square porous cavity using local thermal non-equilibrium model. The radiative transfer equation (RTE) is solved by the discrete ordinates method (DOM) and the energy and momentum equations are solved using finite element method. The results of the present study are compared with that of the other investigations which have used another method to solve radiative transfer equation. Effective parameters on heat transfer and fluid flow characteristics such as Planck number, inter-phase heat transfer coefficient and scattering albedo are studied and the results are presented in the group of dimensionless parameters. The results indicate that the solving method of the radiative transfer equation would have significant effect on the fluid flow and heat transfer characteristic. In the case of low optically thick media, discrete ordinates method (DOM) is more precise than the other methods which used in other literature.

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Hamburger is products of meat that has a lot of consumer due to high nutritional value, in addition to good flavor and its easy to use, also due to lack of chemical additives in its production process. Hawthorn medicinal fruit, with the scientific name of Crataegus elbursensis has gained wide fame in herbal medicine. In this research hamburger is mixed with hawthorn extract (at different concentration of 0, 0/5, 1, 1/5). The antimicrobial effect of hawthorn extract (Crataegus elbursensis) on Salmonella enteric and  Staphylococcus aureus bacteria growth, TBA,PV, TVBN and phenolic compounds  is investigated for a period of 45 days periodically at 0,15,30 and 45days. The resulats of microbial assey showed that mixed Hamburger significantly decreased Salmonella enteric and  Staphylococcus aureus bacteria growth during 45 days storage. Samples that mixed with hawthorn extract showed lower TBA, PV and TVBN values compared to control during the storage time. According to the obtained results, Hawthorn extract was able to Antioxidant and antibacterial effect in hamburger.